A first in Italy: a saturation diving system made available for divers searching for unexploded ordnances

220 columns of gravel installed to stabilise foundation

• Eight divers rely on a saturation diving system as they take turns going to the seabed during a 60-day period to clear area of unexploded ordnances

• Webuild is the first Italian company to use this system as part of the unexploded ordnances clearance in an area to be developed

• Work on seabed proceeds according to schedule

GENOA, August 1, 2023 – An underwater search for unexploded ordnances along the seabed, up to 50 metres in depth, has begun at the site chosen for Genoa’s new breakwater. A first in Italy, Webuild has resorted to divers whose work relies on the use of a saturation diving system. Their search for ordnances will last 60 consecutive days, during which the divers will take turns working on the seabed. 

The breakwater is built by the PERGENOVA BREAKWATER, a consortium led by Webuild in partnership with Fincantieri Infrastructure Opere Marittime, Fincosit and Sidra. Rina is providing project management consulting services. The work has been commissioned by the Western Ligurian Sea Port Authority. For the construction of the breakwater, which will also benefit from financing from the National Plan for Recovery and Resilience (PNRR in Italian), an estimated 1,000 people will be employed, both directly and indirectly.

The search for ordnances, being conducted in coordination with Drafinsub, involves eight divers, who in groups of two are brought down to the seabed inside a submersible decompression chamber to the required depth. Each of the two divers will go out to work for four hours at a time. At the end of the eight-hour shift, they are replaced by another pair of divers. Their work will be coordinated at the surface on a large floating platform on which the saturation diving system will be located. A 1,200 Kw power generator and living quarters for 32 technicians will also be on the platform, allowing them to work throughout the search for ordnances in complete safety. A control room will monitor all the conditions of the submersible decompression chamber and saturation diving system. Work will be carried out 24 hours a day, seven days a week.

Work began on July 7 to consolidate the designated area of the seabed proceeds, having already built some 220 of the 70,000 gravel columns that will ensure the stability of the foundation upon which the breakwater will rest. The laying of gravel on the sea floor is also being carried out at full rhythm. Approximately 200,000 tons of material have already been poured from a ship with a 3,600 ton-capacity and two smaller pontoons of approximately 700 tons in total. They transport on average 3,000 tons of gravel per day and have made more than 90 return trips from Piombino to Genoa. 

The Genoa’s new breakwater is the largest project to be carried out to strengthen the Italian port system. It will protect the port of Genoa from large waves. A unique project in engineering terms, it will measure 6,200 metres in length and replace the existing structure. Its location will be farther out at sea to allow access to the port by ultra large cargo ships, which currently have limited in space to manoeuvre behind the existing breakwater.